Your attorney's recommendations sound pretty standard. In our case, the guardians are also the trustees, but Husband didn't want the money spent at all: not for lessons for the kids, not to continue private school, not to upgrade their house or cars (to accommodate our children!). He was totally unreasonable about it. However, the guardians would get the Social Security, so $4k/mo. And they're well-off as it is, and they agreed to this in advance, so okay.
In his defense, if we inherited their children, he's said we would spend our own money on them and not from their trust, because they're "ours" now.
We put in that the money could be used for education (including tuition, on-campus housing, books, supplies, study abroad, etc) starting at age 16, but each child is only entitled to 4% of the total gross per year for that. Upon completion of a Bachelor's or discontinuing their education, the trustee may only distribute funds to maintain or preserve the health of the child. We did one distribution: when the youngest is 25 the remainder is divided equally, INCLUSIVE of the amount that each used for education. Again, Husband's stipulation. He really wanted to incentivize getting an education quickly and getting out into the world.